You are allowed to put your refferal link on your signature
So, when you make promotion, ask users to join through refferal link on your signature
And you might want to use link shortener, so every user can't know the refferal link
Any you should know it already when you join this forum
Still referral spam.
If you pay people to register under your ref link it works on games and rounds, also sometimes when people find new promos or giveaways they give their ref link and a non ref link, seems to be allowed aswell.
Still referral spam.
It took me a while to find this. Essentially 99% of the referral links get deleted. It depends on who's handling the situation. Your post has to be very constructive, on topic and the normal link has to be visible as well. However, in most cases they get deleted so there isn't really a fixed guideline on posting them either. Also make sure that you do not post it in several threads/posts else everything will be deleted for sure.
You may add the link to your signature space (it is allowed), however there are several restrictions on signatures for low-ranked members (like only 50 characters are permitted in a newbie's signature).